Semiconductor device fabrication is a process used to create integrated circuits that are present in everyday electrical and electronic devices. The fabrication process is a multiple-step sequence of photolithographic and chemical processing steps during which electronic circuits are gradually created on a wafer composed of a semiconducting material. Silicon is an example of a typical semiconductor material used in the fabrication process, however other types of semiconductor materials can be utilized.
Photolithographic steps are processes used to pattern parts of a thin film or layer on a device. A reticle or photoreticle is used to transfer a geometric pattern using a photomask to expose a light sensitive material, referred to as photoresist. Other chemical treatments are then performed to selectively etch material from a semiconductor device and/or to selectively deposit material on/over a semiconductor device.
The photomask is a two dimensional image defining a pattern layer or deposition layer. The photomask is dimensioned to match the reticle. Thus, the photomask has a length and width that correspond to the physical length and width of the reticle.
Generally, formation of an integrated circuit is limited by the size of the photomask. As a consequence, the integrated circuit is also limited by the size of the reticle.